Oil-bearing fluid inclusions (FIs) in minerals such as quartz, carbonates, fluorite etc. contain aliquots of fluids trapped within cavities during crystallization or re-crystallization of secondary cracks in the presence of a fluid phase. Geochemical information from these oil inclusions can be used to compare present and palaeo-oils and to examine migration events and alteration processes that have affected the composition of free oil. While hydrocarbon components have been widely evaluated, very little is known about the polar compounds contained in occluded oils or formation waters. The composition of polars in occluded crude oils gives first-hand information on facies, maturity and migration distance, whereas those in aqueous inclusions yield clues as to oilfield proximity and paleo-OWC.

Organic compounds containing nitrogen, sulfur, and oxygen (NSO compounds) possess functional groups causing an increased polarity, which leads to difficulties in there analyses. Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR MS) affords ultra-high mass accuracy and resolving power, making it possible to identify molecular formulas in complex organic mixtures and to resolve thousands of compounds (especially polar and high molecular weight compounds) in the inclusion that were previously inaccessible.

Goals

• Establishment of a reliable cleaning and extraction method for oil-inclusions in different host minerals
• Unravel the organic matter composition in oil-bearing inclusions using state-of-the-art analytical tools
• Understand petroleum systems using NSO compounds in fluid inclusions, source rock and crude oil

Participants

• Yufu Han, GFZ
• Dr. Mareike Noah, GFZ
• Prof. Brian Horsfield, GEOS4
• Dr. Volker Lüders, GFZ
• Dr. Hans-Martin Schulz, GFZ 

Funding

• IPP (Industry Partnership Programme): Aker BP
• Chinese Scholarship Council (CSC)